<script setup>
import {ref} from 'vue'

const style = ref('style1')

//定义函数
const changeColor = ()=>{ //箭头函数
                          //解包变量使用value
  if (style.value === 'style1'){
    style.value = 'style2'
  }else{
    style.value = 'style1'
  }
}
</script>

<template>
  <div :class="style" @click="changeColor"></div>
</template>

<style scoped>
.style1{
  width: 120px;
  height: 120px;
  background-color: red;
}
.style2{
  width: 200px;
  height: 200px;
  background-color: blue;
}
</style>